Resolve "fix k8s compatibility and update dependencies"

Closes #44 (closed)

Dockerfile

@@ -29,10 +29,11 @@ COPY --from=builder /usr/local/lib/python3.8/site-packages/PyICU-2.8.1.dist-info
 
 # icu-dev package is nevertheless needed by the python library
 # hadolint ignore=DL3018
-RUN adduser -D repdav \
+RUN adduser -D repdav -u 1000 \
     && apk add --no-cache icu-dev
 
-USER repdav
+# use a "numeric" user for k8s compatibility
+USER 1000
 
 COPY --chown=repdav requirements.txt /
 RUN pip install \